Filling stations for dispensing gasoline and other fuels have long had a problem with vehicles pulling away from the fuel dispensing pump with the dispensing nozzle still inserted in the vehicle's tank, or with the nozzle or dispensing hose otherwise secured or hung on the vehicle. Such incidences usually result in damage to the dispensing pump and/or breakage of the dispensing hose. It will be appreciated that repairing the resulting damage to the dispensing pump and hose can be extremely costly. Further, the fuel spillage which can result from such damage can create a dangerous and possibly life threatening condition. Attempts have been made to overcome this problem by installing two hoses joined by a breakaway coupling device on the dispensing pump, with the coupling device designed to disengage and seal the hoses when pressure is exerted on the coupling as in the case where a vehicle pulls away from the pump with the nozzle or hose attached. Certain devices of this type are manufactured by Emco Wheaton, Inc. of Conneaut, Ohio, and Husky Corporation of Pacific, Mo. Further, certain devices are disclosed by U.S. Letters Pat. Nos. 1,551,697; 3,719,194; 3,741,521; 3,788,348; 3,797,510; 4,023,584; and 4,449,545. However, problems have been encountered with conventional breakaway hose coupling devices disengaging during normal operation in response to the fluid pressure surge within the hoses, or "water hammer" effect, created by the abrupt closing of the dispensing nozzle.
Therefore, it is an object of the present invention to provide an improved breakaway hose coupling device for releasably joining the hose ends of two fluid communicating hoses.
Another object of the present invention is to provide an improved breakaway hose coupling device for selectively disengaging and sealing the hose ends of two hoses in response to a disengaging force in excess of a preselected value being exerted on the coupling device.
Still another object of the present invention is to provide an improved breakaway hose coupling device which is less disruptive of fluid flow than conventional coupling devices.
Yet another object of the present invention is to provide a breakaway hose coupling device which is less susceptible to disengaging as a result of the fluid pressure surge created by the abrupt closing of the associated dispensing nozzle.
A further object of the present invention is to provide an improved breakaway hose coupling device which is easy to install and is less susceptible to shear pin damage upon installation.
Another object of the present invention is to provide an improved breakaway hose coupling device which is inexpensive to manufacture and maintain.